Development: Controversial plan calls for nonindustrial uses of rail yards near downtown. Critics cite costs and need for projects that would create jobs.

Boosters of the Los Angeles River proposed controversial initiatives on Saturday to convert two railroad yards near downtown into a riverfront park west of San Fernando Road and a new canal lined with housing, shops and sports fields on Chinatown's east side.

Those ideas for the Taylor and former Southern Pacific train yards were put forward at "The River Through Downtown" conference at the Central Library, attended by about 200 people, including federal, state and local officials.

Some skepticism was raised about costs and anticipated zoning battles to block industrial development. Keynote speaker Rep. Xavier Becerra, although supportive of river restoration, warned that some area residents want jobs and new supermarkets most of all. "There will be a point when there will be conflict," the Los Angeles Democrat said.

But many participants stressed that timing is crucial because the railroad yards are for sale. And they said government funding to acquire portions of the land may be available, although no solid cost estimates were offered.

"This kind of opportunity is a once-in-a-hundred-years opportunity," said architect Arthur Golding.

He helped design the proposal to divert river water into the former yards east of Broadway in Chinatown and create a 50-acre neighborhood, laced with bridges and sports fields, around a waterway. This River Park concept would revive the canal system that early Spanish settlers built to irrigate farms near the original pueblo of Los Angeles.

That Chinatown plan, and one for a park at Taylor Yard about a mile and a half to the north, tap into current concerns about El Nino storms. The Chinatown canal is intended to serve as a backup flood control basin.

A similar role is envisioned for Taylor Yard, where dredging polluted soil would create a crescent-shaped river tributary. An existing Union Pacific rail line would be shifted eastward and elevated in spots. Low-rise retail and light industrial buildings would be built close to San Fernando Road, and two new bridges, one just for pedestrians, would cross the river and connect the isolated Cypress Park district to the river's west bank.

Taylor Yard, about 160 acres between the river's east bank and San Fernando Road south of the Glendale Freeway, has been mainly empty since the early '80s. Union Pacific recently agreed to sell about 90 acres for warehouses, film industry-related facilities and retail centers in deals that Mayor Richard Riordan supports, but that state Sen. Richard G. Polanco (D-Los Angeles) and river activists pledged Saturday to fight.

"Taylor Yard should be treated with as much care for the Eastside as Playa Vista is receiving for the Westside," said architect Kate Diamond, who worked on the Taylor Yard park idea. She referred to the lengthy debates and studies about the massive Playa Vista development, including the proposed DreamWorks SKG studio, on the Westside's Ballona Creek.

An aide to Riordan, who asked not to be identified, estimated that it would cost about $50 million to clean up the toxic wastes and buy half of Taylor Yard for a park. Many additional millions would be needed to build the tributary and recreation facilities, he added. "That would be very difficult to raise," he said.

Also discussed Saturday were possible bikeway connections between paths along the Los Angeles River and the Arroyo Seco and bicycle routes into Union Station in downtown. At certain points, that could require elevated bike bridges, perhaps attached to structures for the proposed Blue Line commuter rail project to Pasadena.

The conference was sponsored by Friends of the Los Angeles River, the Sierra Club and other environmental, civic and design organizations.

Speakers repeatedly referred to cities such as San Antonio and Brisbane, Australia, which have revived their downtowns with riverfront parks and commercial districts. The same could happen here, they stressed.

"I think it is impossible to exaggerate the importance of the river to downtown," said Dan Rosenfeld, real estate assets manager for the city of Los Angeles.